STR PRSBO5 Dana 60 Replacement for Mopar A,B,E-body. Bolt in Dana 60 assembly includes 35 spline axles, 1/2” studs, axle bearings, Trac-Lok posi unit, standard gear set, 1350 series yoke, chrome cover, breather vent, filler and drain plug fully set up. Gear ratios: 3.54, 3.73, 4.10, 4.30, 4.56, 4.88, 5.13, 5.87. Pro Gears (for drag race only) available up to 6.50 ratio. Other options include 5/8” dia. wheel studs, Pro gears, Spool, Detroit Locker, Trutrac, LPW cover (stronger cast aluminum), 4130 Chromoly yoke, 40 spline axles (if using spool), pinion snubber, and disc brakes. Please allow two to three weeks for assembly. Each rearend is custom built for your specific application and therefore unreturnable. Wilwood brakes are 12.19" rotors with internal parking brake and 4-piston calipers. Explanation of various differentials: Standard Track-Lok is a 2-pinion design ideal for use on street and mild track use. TrueTrac is a worm gear design and has better traction than a Trac-Lok and is smoother than a Locker. Locker is the strongest streetable unit but not as quiet as a True-Trac or Trac-Lok.